stepper motor vibrates

i connected a stepper motor to motor driver v1.2. it works with an arduino uno with a grooove shield. i used the example code (stepper demo code.ino) ,
i powered the shield with 12 v from a power supply (max 5A). the stepper vibrates but does not turn.
i tried another motor driver to check if the board was damaged, but got the same result

what should be changed? timing is at 4 in the code. the motor is ok, it works with a polulu driver

tnx

If the motor just vibrates, it is probably connected incorrectly.